|IUPAC name||Ethanoyl chloride|
|Other names||Acetyl chloride|
3D model (JSmol)
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|Molar mass||78.5 g/mol|
|Density||1.11 g/ml, liquid|
|Dipole moment||2.45 D|
|S-phrases||, , , ,|
|Except where noted otherwise, data are given for|
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references
Acetyl chloride, also known as ethanoyl chloride, is an acid chloride (also known as an acyl chloride) derived from acetic acid (ethanoic acid). It has the formula CH3COCl and it belongs to the class of organic compounds called acyl halides. At room temperature and pressure, it is a clear colorless liquid. Acetyl chloride does not exist in nature, because contact with water would hydrolyze it into acetic acid and hydrogen chloride. In fact, if handled in open air it gives of white smoke owing to the hydrolysis from the moisture in the air. The smoke is actually gaseous hydrogen chloride which forms small droplets in the air with water vapour.
- CH3COO-H + O=SCl2 → CH3COCl + SO2 + H-Cl
It is a reagent for acetylation in the synthesis or derivatization of chemical compounds. Examples of acetylation reactions include acylation processes such as esterification (see below) and the Friedel-Crafts reaction).
Frequently such acylations are carried out in the presence of a base such as pyridine, triethylamine, or DMAP, which as catalysts help to promote the reaction and as bases neutralize the resulting HCl.
For further information on the types of chemical reactions compounds such as acetyl chloride can undergo, see acyl halide.